The Practical Zone System for Film and Digital Photography, 5th Edition

chapter two   

Print Quality, Negative Contrast, and Dynamic Range

Let’s begin by defining a few important terms. Throughout this book you will find that the word contrast has different meanings depending on whether I am referring to the contrast of the subject you are photographing or the negative or digital file that you will use to make the print. In general, the word “contrast” refers to the relative difference between dark and light areas of the subject or negative or in your digital image.

Subject contrast refers to the difference between the amounts of light reflected by the darker, or “shadow,” areas of the scene and the lighter, or “highlight,” ...